There are three types of inductors, namely thin film type inductors, multilayered type inductors, and wire wound type inductors, which are commercially available.
TW patent application publication No. 201440090 A discloses a multilayered type inductor (see FIG. 1) and a method of making the same.
The method of making the multilayered type inductor includes the steps of: laminating a first circuit plate 110, a second circuit plate 120, a third circuit plate 130 and a fourth circuit plate 140 (see FIG. 2A); attaching an assembly of a supporting film 150 and a bonding pad circuit 160 to the first circuit plate 110 (see FIG. 2B); transferring the bonding pad circuit 160 from the supporting film 150 to the first circuit plate 110 (see FIG. 2C); removing the supporting film 150 from the bonding pad circuit 160 (see FIG. 2D); sintering the first, second, third and fourth circuit plates 110, 120, 130, 140 and the bonding pad circuit 160 so as to form a multilayered substrate 100 (see FIG. 2E); and scribing the multilayered substrate 100 using a scriber 170 (see FIG. 2F), so that the multilayered substrate 100 can be broken into a plurality of multilayered type inductors 10 (see FIG. 1).
Referring to FIG. 1, each of the first, second, third and fourth circuit plates 110, 120, 130, 140 includes a respective one of non-magnetic bodies 111, 121, 131, 141 and a respective one of first, second, third and fourth circuit patterns 112, 122, 132, 142. Formation of the first, second, third and fourth circuit plates 110, 120, 130, 140 requires numerous steps (a total of at least 13 steps), including punching each non-magnetic body 111, 121, 131, 141 to form the holes, filling the conductive paste in the holes, and forming the first, second, third and fourth circuit patterns 112, 122, 132, 142, and sintering before laminating the first, second, third and fourth circuit plates 110, 120, 130, 140.
The aforesaid method is relatively complicate, and the bonding strength between the first, second, third and fourth circuit patterns 112, 122, 132, 142 may be insufficient. There is still a need to simplify both the structure of the multilayered type inductor and the method of making the same.